The purpose of this research is to explore the fundamental physical and biological principles involved in the application of electro-osmosis to the introduction and removal of cryoprotective agents for the cryoprotection of red blood cells. Preliminary experiments indicate that this technique can make possible a red cell freezing protocol in which the cells are glycerolized, frozen, deglycerolized and administered without being removed from a single container. The technique has the potential of substantially reducing the cost of frozen red cells and of making possible an extension of the currently restrictive 24 hour post-thaw outdate. We propose to construct prototype blood bags incorporating ion exchange membranes, to explore the effect of variables such as bag geometry, current density, alternation of polarity, mixing of the blood suspension, salt concentration, red cell hematocrit and temperature. Based on the data obtained, optimum programs will be selected and incorporated into prototype apparatus to enable an evaluation of the quality of the final product. These evaluations will consist of both in vitro and in vivo assays of a wide variety of red cell properties. The ultimate goal of the project is to provide a procedure for glycerolizing and deglycerolizing red cells that is sufficiently safe, simple and economical to render frozen red cells cost-effective for a wider variety of applications including inventory control.